/*-
 * PhonebookPoller.java
 *
 * $LastChangedBy:  $
 * $LastChangedRevision:  $
 * $LastChangedDate:  $
 * $HeadURL: $
 *
 * Copyright (c) 2008, Stein Gunnar Bakkeby
 * All rights reserved.
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of Stein Gunnar Bakkeby nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package com.googlecode.attention.services;

import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

import com.googlecode.attention.PhonebookEntry;
import com.googlecode.attention.at.AtListener;
import com.googlecode.attention.at.Gateway;
import com.googlecode.attention.at.ReadPhonebookEntries;
import com.googlecode.attention.util.Settings;



public class PhonebookPoller implements AtListener<ReadPhonebookEntries> {

  private Gateway gateway;
  private final Lock lock = new ReentrantLock();
  private final Condition feedbackArrived = lock.newCondition();
  private ReadPhonebookEntries feedback;
  
  /* Settings from configuration file */
  private int phonebookTimeout;
  private int gatewayTimeout;
  
  public PhonebookPoller(final Gateway gateway, final Settings settings) {
    this.gateway = gateway;

    loadConfiguration(settings);
  }
  
  private void loadConfiguration(final Settings settings) {
    phonebookTimeout = settings.getInteger("phonebook_timeout");
    gatewayTimeout = settings.getInteger("gateway_timeout");
  }
  
  public PhonebookEntry[] poll() {
    lock.lock();
    pollPhonebookInfo();
    try {
      feedbackArrived.await(phonebookTimeout, TimeUnit.SECONDS);
    } catch (InterruptedException e) {
      System.out.println(e.getMessage());
      // TODO log
    } finally {
      lock.unlock();
    }
    
    return (feedback == null ? new PhonebookEntry[0]
                             : feedback.getPhonebookEntries());
  }
  
  public PhonebookEntry poll(final int memoryIndex) {
    lock.lock();
    final ReadPhonebookEntries rpe = new ReadPhonebookEntries(this);
    rpe.prepareExecute(memoryIndex);
    gateway.addAT(rpe);
    try {
      feedbackArrived.await(gatewayTimeout, TimeUnit.SECONDS);
    } catch (InterruptedException e) {
      System.out.println(e.getMessage());
      // TODO log
    } finally {
      lock.unlock();
    }
    if (feedback != null) {
      PhonebookEntry[] entries = feedback.getPhonebookEntries();
      if (entries.length > 0) {
        return entries[0];
      }
    }
    return null;
  }
  
  public void pollPhonebookInfo() {
    final ReadPhonebookEntries rpe = new ReadPhonebookEntries(this);
    rpe.prepareTest();
    gateway.addAT(rpe);
  }
  
  public void atFailure(final ReadPhonebookEntries command) {
    /* 
     * Even though a reported failure this could just mean that because the
     * transfer of phonebook entries can be slow, the final OK may be missed
     * if the mobile has a large phonebook entry range to go through.
     * 
     * For example if the command "AT+CPBR=1,200" is sent and the phone only
     * holds, say, 70 of those 200 possible entries, then there will be a time
     * of no response while the mobile runs through and checks the last 130
     * empty entries. 
     */
    feedback = command;
    lock.lock();
    feedbackArrived.signal();
    lock.unlock();
  }

  public void atSuccess(final ReadPhonebookEntries command) {
    switch (command.getTypeOfCommand()) {
    case TEST:
      command.prepareExecute();
      gateway.addAT(command);
      break;
      
    default:
    case EXECUTE:
      feedback = command;
      lock.lock();
      feedbackArrived.signal();
      lock.unlock();
      break;
    }
  }
}
